The present invention relates to a discharging or drawing device for a continuous caster. More particularly, the present invention relates to a discharge or drawing device for a continuous metal caster of the type wherein the drive shaft of a drive or discharging roller, which is in engagement with the profile of the casting to be drawn, is charged or driven by a drive member (power source) via a drive mechanism so that the drive roller may be intermittently driven in opposite directions.
In the casting of metal by means of a continuous caster, and in order to provide a good quality casting, it is known to provide a drawing or discharge device for the caster which operates to provide intermittent withdrawal or drawing of the casting from the caster. In this mode of operation, the discharge device engages the profile or skin of the casting and intermittently applies a force to the casting in the drawing direction followed by a force in the opposite direction, i.e. toward the caster.
In such discharging devices of the prior art, a stepping motor is generally provided to produce the drawing movement for the profile to be drawn, e.g. a wire, rod, strip or pipe, with the aid of a drive roller. Such devices, however, require high expenditures for the electronic systems to control the stepping motor. Additionally, such a stepping motor is both expensive to acquire and to maintenance.
A discharge device for a horizontal continuous caster for steel is known (see e.g., Federal Republic of Germany DEOS No. 3,148,033) wherein two sets of profiled drive rollers are utilized, with each roller of both sets being provided with a separate drive motor, and with the respective sets of drive rollers being continuously driven in opposite directions. The two sets of rollers are mounted and controlled so that they selectively engage the casting profile at different times to provide the two directions for force on the casting. As can easily be appreciated, such an arrangement includes two independent roll stands, again resulting in high expenditure for acquisition and maintenance.
Also known are hydraulic tensioning and drawing devices. However, these have the drawback that the tensioning device must always move back in the open state and the time required for the return movement limits the total discharging speed. Moreover, this device produces the operating noises customary for hydraulic systems.